Mode processing circuit

ABSTRACT

A mode processing circuit for a multi-operation mode electronic apparatus including a mode stack having a plurality of stages in which an input command signal is stored as an operation mode of the multi-operation mode electronic apparatus, wherein the operation mode inputted to the mode stack is sequentially stored and optimized and the optimized operation mode is read out from the mode stack in the sequential order and then executed after the transition of the operation mode is ended.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mode processing circuit for amultiple operation mode electronic apparatus such as a video taperecorder, a tape deck, a video disc player, a compact disc player and soon.

2. Description of the Prior Art

Various operation modes, such as a playback mode, a rewind mode and thelike are available in a known video tape recorder (hereinafter simplyreferred to as a VTR). To change these operation modes, it is necessaryto switch the VTR or to move its brake and pinch roller into and out ofengagement.

If a plunger is used to switch the mechanism, the change of theoperation mode can be made substantially in a moment. The employment ofthe plunger, however, causes a large current to flow upon its actuation.Also, in the normal operation mode, a current must flow continuously,requiring a large power supply circuit which consumes a large amount ofpower.

It is therefore proposed to employ a motor instead of the plunger. Whena motor is used together with a gear mechanism, atthough it is small insize, the necessary driving power to switch the mechanism is generated.Further, the employment of the motor can reduce the power consumptionand allow the power supply circuit to be small in size. However, when amotor is used to switch the mechanism, the transition (switching) of itsmode takes a lot of time. For example, it takes about 2 seconds for theVTR to change from the stop mode (STOP) to the playback mode (PB); ittakes about 1.5 seconds for the VTR to change from the playback mode(PB) to the stop mode (STOP); and it takes about 1.8 seconds for the VTRto change from the stop mode (STOP) to the recording mode (REC).

Accordingly, when a user intends to press a second operation key after afirst operation key has been depressed, the user must not press thesecond operation key until the VTR finishes changing to the modecommanded by the first key.

This is very inconvenient for the user, so it is proposed to stack inputcommands issued by pressing the operation keys.

Let it now be assumed that as, for example, illustrated in FIG. 1, theVTR is placed in the stop mode before time point t₁ and that a recordingkey is pressed at time point t₁. Then, the mode of the VTR (mechanism)begins to change from the stop mode to the recording mode at time pointt₁.

If a stop key, for example, is pressed at time point t₂ during thistransition period, this stop key is valid for the recording mode whichis the mode after the mode is changed, so that the command instructingnot the recording mode but the stop mode after the mode transition, isstacked in the mode stack.

When the mode transition of the VTR is ended at time point t₃, the VTRis placed in the recording mode (REC). At that time, the stop modecommand stacked in the mode stack at time point t₂ is read out and theprocessing of this command is executed.

Accordingly, the VTR begins the transfer to the stop mode at time pointt₃ and is placed in the stop mode at time point t₄. Even though a pausekey is pressed at time point t₅ in the stop mode, the pause mode (PAUSE)is useless for the stop mode. Hence, the command issued by pressing thepause key is not executed.

As described above, according to this mode stack system, it becomesposiible to remove the cumbersome requirement that the user must notpress the next operation key until the mode transition of the VTR isended (even if the next key is pressed, this will be neglected).However, the above mentioned mode stack system has the following defect.

If the stop key is pressed at time point t₂ and the pause key is thenpressed at time point t_(a) as, for example, shown in FIG. 2, since thispause key is valid for the recording mode, which is the mode after themode transition (if the pause key is depressed in the recording mode,the VTR is placed in the recording pause mode (REC PAUSE)), and the modestacked in the mode stack is changed again from the stop mode to therecording pause mode.

Accordingly, the mode of the VTR is moved to the recording pause mode attime point t₃ and the VTR is placed in the recording pause mode at timepoint t₄.

Although the stop key and the pause key are pressed in the samesequential order as that of FIG. 1, the VTR is placed in an operationmode different from that in FIG. 1 in this case because of the timing ofthe depression of the pause key vis-a-vis the actual mode shifting ofthe VTR.

In other words, if a plurality of valid operation keys are depressedduring the mode transition period, the mode stacked in the mode stack isrenewed to the mode suggested by the operation key that was last pressedby the user and the modes commanded by the previously-pressed operationkeys are all neglected. Accordingly, the operation mode of the VTRbecomes different depending on the timing at which the user presses theoperation keys (depending on whether the VTR mode was in the process ofbeing changed or was already changed when the keys were pressed).

To overcome the above mentioned shortcomings, an improved mode stacksystem is proposed, in which the mode stack is arranged to have aplurality of stages to sequentially stack the input modes and to executethe modes sequentially.

This mode stack system having a plurality of stages, however, mustremove useless or invalid modes stacked in the mode stack by optimizingthe mode stacked. This makes a program of a mode control microcomputercomplicated and takes a lot of time for such removal. This defectbecomes serious particularly when 8-bit mode data is processed by a CPU(central processing unit) which is capable of providing only a 4-bitcomparing command. Further, an area for the mode stack must be providedin a RAM.

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, it is a general object of this invention to provide animproved mode processing circuit for a multi-operation mode electronicapparatus, such as a VTR.

A more specific object of this invention is to provide an improved modeprocessing circuit for a multi-operation mode electronic apparatus, bywhich an operation mode can be changed in the shortest period of time toa desired operation mode when an operation key is pressed.

Another object of this invention is to provide a mode processing circuitfor a multi-operation mode electronic apparatus in which the apparenttime required by the mode transition can be removed.

A further object of this invention is to provide a mode processingcircuit for a multi-operation mode electronic apparatus in which the VTRcan be placed in the same final mode by pressing the correspondingoperation key at any time.

Yet a further object of this invention is to provide a mode processingcircuit for a multi-operation mode electronic apparatus in which theoptimizing operation becomes unnecessary, so that the program of themode controller is simplified, taking less time.

Still a further object of this invention is to provide a mode processingcircuit for a multi-operation mode electronic apparatus which does notrequire a stack area.

Still a further object of this invention is to provide a mode processingcircuit for use with a multi-operation mode electronic apparatus, suchas a video tape recorder, a tape deck, a video disc player, a compactdisc player and so on.

According to one aspect of the present invention, there is provided amode processing circuit for a multi-operation mode electronic apparatuscomprising:

a mode stack for receiving and storing operation mode commands for saidmulti-operation mode electronic apparatus;

means for sequentially storing said operation mode commands received bysaid mode stack and for optimizing the same; and

means for deriving said optimized operation mode commands from said modestack in the sequential order and then executing the same after thetransition of said operation mode is ended.

According to another aspect of the present invention, there is provideda mode processing circuit for a multi-operation mode electronicapparatus comprising:

a transition vector look-up table memory means for indicating anoperation mode to which the operation mode of said multi-operation modeelectronic apparatus should be shifted;

means for determining a final mode of said multi-operation modeelectronic apparatus in accordance with an input command;

means for determining a new operation mode to which the operation modeof said multi-operation mode electronic apparatus is to be shifted nextfrom said final mode and a mode to which the operation mode of saidmulti-operation mode electronic apparatus was shifted with reference tosaid transition vector look-up table memory means; and

means for changing the operation mode of said multi-operation modeelectronic apparatus to said operation mode thus determined and thenplacing said multi-operation mode electronic apparatus in said finalmode.

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptionof the preferred embodiments that are to be read in conjunction with theaccompanying drawings, throughout which like reference numerals identifylike elements and parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a mode transition diagram used to explain a known mode stacksystem for a video tape recorder;

FIG. 2 is another mode transition diagram used to explain the same knownmode stack system for a video tape recorder;

FIG. 3 is a block diagram of an embodiment of a mode processing circuitaccording to the present invention, illustrating hardware relating tothe mode transition operation of a video tape recorder;

FIG. 4 is a mode transition diagram used to explain the presentinvention;

FIG. 5 is a flow chart used to explain the mode transition operation inassociation with the mode transition diagram of FIG. 4;

FIG. 6 is a table used to explain an algorithm of the mode transitionand the change of data stacked in a mode stack;

FIG. 7 is a diagram used to explain the mode stack of the invention;

FIGS. 8, 9, 10 and 11 are respectively diagrams used to explain the modetransition operation and the mode stack of the invention;

FIG. 12 is a mode transition table used to explain another embodiment ofthe mode processing circuit for a multi-operation mode electronicapparatus according to the present invention;

FIG. 13 is a transition vector table used to explain the operation ofthe present invention;

FIG. 14 is a mode transition diagram used to explain the operation ofthe present invention; and

FIG. 15 is a flow chart used to explain the operation of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, the present invention will hereinafter be described in detail withreference to the drawings.

FIG. 3 illustrates hardware relating to the mode transition operation ofthe VTR according to the present invention.

Referring to FIG. 3, there is shown a mechanism (VTR) control section 1which includes a loading motor 11 for loading or unloading a tape on orfrom the VTR, a control motor 12 for controlling the mode of the VTR anda servo circuit 13 for controlling a drum and a capstan of the VTR.

A mode controller 2 is formed of a microcomputer whose output issupplied to the control section 1 to place the VTR in each operationmode. At the same time, a signal indicative of the state (mode) of theVTR is supplied from the control section 1 to the mode controller 2.

Key input means 3 is provided with a plurality of operation keys (notshown). A receiving circuit 4 is adapted to receive a signal inputted bythe operation key of a remote controller (not shown) when the VTR isoperated by the remote controller. The key input signals from the keyinput means 3 and the receiving circuit 4 are both supplied to the modecontroller 2. Mode indicating means 5 visually indicates to the user,e.g. by an LCD display, the mode in which the VTR is placed, on thebasis of the output signal from the mode controller 2.

The mode stack is provided within a RAM (random access memory) of themicrocomputer which forms the mode controller 2.

When the operation key of the key inputting means 3 or the operation keyof the remote controller (not shown) is pressed, its command isprocessed by the mode controller 2 and the processed result or data issupplied to the control section 1, so that the control section 1 isoperated so as to place the VTR in a predetermined operation mode. Atthe same time, the corresponding mode of the VTR is visually indicatedby the mode indicating means 5.

FIG. 4 illustrates, by way of example, how the VTR mode and data stackedin the mode stack are changed with the command inputted when theoperation key is pressed at a certain time point.

In the description below, "present mode" and "final mode" arerespectively defined as follows: the "present mode" indicates the modeof the VTR at that certain time point and also indicates, during themode transition period of the VTR, the net mode to which the VTR is tobe placed; and the "final mode" indicates the mode stored last in themode controller 2 at that certain time point. The final mode becomes thesame as the present mode when no mode data is stacked in the mode stackat all. Validity of the operation key pressed is judged depending uponwhether the operation key pressed is valid for the final mode or not.The mode indicating means 5 visually indicates the final mode.

In the illustrated example of FIG. 4, since the VTR is placed in thestop mode before time point t₁, the present mode is the stop mode. Atthe same time, no mode is stacked in the mode stack and the final modeand the visual indication thereof are the stop mode.

When the recording key is pressed at time point t₁, this recording modeis valid for the final mode (stop mode), so that "REC" (recording mode)is stacked in the first stage of the mode stack. However, since the VTRhas not yet started changing its operation mode, the VTR immediatelystarts changing its mode from the stop mode to the recording mode, and"REC" is indicated by the mode indicating means 5. Further, the "REC"mode command stacked in the mode stack is removed.

If the stop key is pressed at time point t₂ while the VTR is changingits mode, the stop mode is valid for the final mode (recording mode), sothat "STOP" (stop mode) is stacked in the first stage of the mode stackand the final mode and the visual indication thereof are made the stopmode. However, the VTR itself is changing its operation mode into therecording mode (present mode) which was dsignated by the key input attime point t₁.

When the pause key is pressed at time point t₃, while the VTR is in themode transition period, the pause mode is invalid for the final mode(stop mode), so that this key input is neglected, leaving the modestack, the final mode and the visual indication unchanged.

When the rewind key is pressed at time point t₄, while the VTR is in themode transition period, the rewind mode is valid for the final mode(stop mode), so that "REW" (rewind mode) is stacked in the second stageof the mode stack and the final mode and the visual indication thereofare made the rewind mode. However, the VTR itself is still in theprocess of changing its operation mode into the recording mode (presentmode) which was designated by the key input at time point t₁.

When the stop key is pressed at time point t₅ while the VTR is in themode transition period, the stop mode is valid for the final mode(rewind mode), so that "STOP" (stop mode) is stacked in the third stageof the mode stack. At that time, since the same "STOP" (stop mode) isalso stacked in the first stage of the mode stack, "STOP" and "REW"stacked respectively in the first and second stages of the mode stackare removed and "STOP" stacked in the third stage of the mode stack istransferred to the first stage of the mode stack. This processing is anexample of what may be called "optimization". In that case, the finalmode and the visual indication thereof are made stop mode.

When the playback key is pressed at time point t₆, while the VTR is inthe mode transition period, the playback mode is valid for the finalmode (stop mode), so that "PB" (playback mode) is stacked in the secondstage of the mode stack and the final mode and the visual indicationthereof are made the playback mode.

When the fast forward key is pressed continuously from the time point t₇while the VTR is in the mode transition period, the fast forward mode isvalid for the final mode (playback mode). At the same time, upon theplayback mode, the fast forward key is pressed in the cue mode, so that"CUE" (cue mode) is stacked in the third stage of the mode stack and thefinal mode and the visual indication thereof are made the cue mode.

At time point t₈, when the VTR finishes changing its operation mode intothe recording mode designated by the key input at time point t₁, themode stack is checked. In this case, since "STOP" is stacked in thefirst stage of the mode stack, this "STOP" is set to the present modeand the VTR therefore starts changing its operation mode to the stopmode at time point t₉ (≅t₈). When it is confirmed that the operationmode of the VTR is to be changed to the stop mode, "PB" stacked in thesecond stage of the mode stack is transferred to the first stage thereofand "CUE" stacked in the third stage of the mode stack is transferred tothe second stage thereof, making the third stage of the mode stackempty.

When the VTR has finished changing its operation mode to the stop modeat time point t₁₀, the mode stack is checked. In this case, since "PB"is stacked in the first stage of the mode stack, this "PB" is set to thepresent mode, so that the VTR starts changing its operation mode to theplayback mode at time point t₁₁ (≅t₁₀). After it is confirmed that theoperation mode of the VTR was changed to the playback mode, "CUE"stacked in the second stage of the mode stack is transferred to thefirst stage thereof, thus making the second stage of the mode stackempty.

When the VTR has finished changing its mode to the playback mode at timepoint t₁₂, the mode stack is checked. Since "CUE" is stacked in thefirst stage of the mode stack, this "CUE" is set to the present mode, sothat the VTR starts changing its operation mode into to the cue mode attime point t₁₃ (≅t₁₂). After it is confirmed that the operation mode ofthe VTR was changed to the cue mode, the mode stack is made empty. Inthis way, the VTR is placed in the cue mode after time point t₁₃.

While the operation mode of the VTR and mode data stacked in the modestack are changed as described above, this will be also explained withreference to a general algorithm which is represented in the form of aflow chart in FIG. 5.

This algorithm is exemplified in the flow chart (FIG. 5) of the programthat the microcomputer forming the mode controller 2 (FIG. 3) executes.

The presence or absence of the command (key input) inputted by theoperation key is checked, as represented at decisional step 21 in FIG.5. If the command exists, the processing of the microcomputer (modecontroller 2) goes from step 21 to decisional step 22. Then, it ischecked, as represented at decisional step 22, whether or not the keyinput of which the presence was confirmed at step 21 is valid for thefinal mode. The validity of the key input relative to the final mode ischecked on the basis of a mode transition look-up table which forms, forexample, FIG. 6. Such a look-up table can be store within a ROM (readonly memory) which forms the mode controller 2 (FIG. 3). This modetransition look-up table of FIG. 6 reads as follows.

If the recording key ("REC") is pressed when the final mode is, forexample, the playback ("PB") mode, it is judged that this recording keyis invalid for the final mode, however, if the pause key is pressedinstead, it is judged that this pause key is valid for the final modeand the final mode is renewed to "PB PAUSE" (playback pause mode).

If the key input is judged to be valid as represented at decisional step22, the processing of the microcomputer goes from step 22 to step 23. Asrepresented at step 23, the final mode and the visual indication thereofare renewed at time point t₄ shown, for example, in FIG. 4 and in FIG. 7(reference letters A to E throughout FIGS. 7 to 11 respectivelydesignate operation modes) in accordance with the mode transitionlook-up table of FIG. 6. Then, the operation mode renewed is stacked inthe mode stack.

The processing of the microcomputer goes from step 23 to the nextdecisional step 31. It is checked, as represented at decisional step 31,whether or not a mode which is the same as the renewed final mode isstacked in the mode stack. If not, the processing of the microcomputergoes from step 31 to decisional step 33.

If on the other hand the same mode is stacked in the mode stack, as forexample shown at time point t₅ in FIG. 4 and as illustrated in FIG. 8,the processing of the microcomputer goes from step 31 to the next step32. As represented at step 32, the modes, beginning from the mode (Bmode in the second stage) which is the same as the final mode renewed inthe mode stack up to the mode (D mode) just one stage before the finalstage of the mode stack, are removed as unnecessary modes and the finalmode renewed is shifted to the prior stage of the mode stack. Thisprocessing forms a part of "optimization".

Then, the processing of the microcomputer goes from step 32 (or step 31)to decisional step 33 where it is checked whether or not a mode whichcan be changed directly to the final mode is stacked in the mode stack,thereby omitting unnecessary intermediate modes. If not, the processingof the microcomputer goes from step 33 to decisional step 41. If on theother hand such a mode is stacked in the mode stack, the processing ofthe microcomputer goes from step 33 to step 34. At step 34, as shown inFIG. 9, the modes between the mode (B mode), which can be changed to thefinal mode, and the final mode (E mode) are removed and the final mode(E mode) is shifted to the stage of the mode stack subsequent to themode which can be changed to the final mode (B mode). This processingalso forms a part of "optimization".

The processing of the microcomputer goes from step 34 (or step 33) tothe next decisional step 41. Also, if the absence of a key input isdetermined, as represented at decisional step 21, or if the key input isinvalid for the final mode, as represented at decisional step 22, theprocessing of the microcomputer goes directly from step 21 or 22 to thedecisional step 41.

At decisional step 41 the microcomputer checks whether the VTR is nowchanging its operation mode or has finished its mode changing. If theVTR is changing its operation mode, the processing of the microcomputergoes from step 41 to the next decisional step 42 where the microcomputerchecks whether a mode which is the same as the present mode exists inthe mode stack or not. If not, the processing of the microcomputer goesfrom step 42 to decisional step 44. If the same mode exists in the modestack as represented at decisional step 42, as shown, for example, inFIG. 10, the processing of the microcomputer goes from step 42 to step43. As represented at step 43, the modes from the mode (A mode) of thefirst stage to the mode (C mode) which is the same as the mode which isunder transition, are removed and the next mode (D mode) is shiftedforward (to the first stage of the mode stack). This processing alsoforms a part of "optimization".

Subsequently, the processing of the microcomputer goes from step 43 (orstep 42) to the next decisional step 44 where it is checked whether ornot there is a mode in the mode stack to which the present mode of theVTR in its transition period can be directly shifted, as for example,shown in FIG. 11 (mode A can be shifted to mode D). If not, theprocessing of the microcomputer returns from step 44 to the decisionalstep 21. If such a mode exists in the mode stack the processing goesfrom step 44 to step 45.

At step 45 the modes from the mode in the first stage to the mode (Cmode) which is located just before the transferrable mode are removedand the succeeding mode (D mode) is shifted forward in the mode stack,so that "optimization" is carried out. Then, the processing of themicrocomputer goes back to step 21.

If it is determined, as represented at decisional step 41, that the VTRhas already finished changing its operation mode, the processing of themicrocomputer goes from step 41 to decisional step 51. It is thenchecked, as represented at decisional step 51, whether or not any modecommand remains stacked in the mode stack. If no mode is stacked in themode stack, the processing of the microcomputer goes back from step 51to step 21. If, on the other hand, one or more modes remain stacked inthe mode stack, the processing of the microcomputer goes from step 51 tostep 52 where the present mode of the VTR begins to change into the modeof the first stage in the mode stack. If it is confirmed that the changeof the operation mode of the VTR is started, the mode of the first stagein the mode stack is removed and the next mode is shifted forward.Subsequently, the processing of the microcomputer goes back from step 52to step 21.

Therefore, according to the above described processing routine, theoperation mode of the VTR is changed as, for example, shown in FIG. 4.

Alternatively, the presence or absence of the key input can be checkedby executing the condition determining command instead of using the modetransition look-up table, as represented at decisional step 21.

Furthermore, the present invention is not limited to a VTR (mechanism)but can similarly be applied to various other kinds of multi-operationmode electronic apparatus, such as, a tape deck, a video disc player ora compact disc (CD) player and the like which require a lot of time tochange their operation modes.

Another embodiment of the mode processing circuit according to thepresent invention will now be described. This embodiment is similar tothat shown in FIG. 3 but in this embodiment, a mode transition look-uptable and a mode transition vector look-up table shown, for example, inFIGS. 12 and 13 are provided within a ROM (read only memory) which formsthe mode controller 2 (FIG. 3).

When the operation key of the inputting means 3 or the operation key ofthe remote controller (not shown) is pressed, the input data or commandis similarly supplied to the mode controller 2, in which it isprocessed. The processed result or data therefrom is then supplied tothe control section 1, whereby the control section 1 is so operated asto place, for example, the VTR in the predetermined operation mode andthe operation mode in which the VTR is just placed is visually indicatedby the mode indicating means 5 similar to the first embodiment.

FIG. 14 illustrates an example in which the operation mode of the VTR ischanged with the command inputted by the operation key using this secondembodiment.

In the description below, "present mode" and "final mode" arerespectively defined as follows: the "present mode" indicates the modein which the VTR is now placed at a certain time point and alsoindicates the next operation mode of the VTR during the mode transitionperiod; and the "final mode" indicates the mode stored last in the modecontroller 2 at that time point. The validity of the operation keypressed is determined depending upon whether the operation key pressedis valid for the final mode or not. The mode indicating means 5 visuallyindicates the final mode.

The areas in which the present mode and the final mode are stored areformed within the RAM of the microcomputer forming the mode controller2.

In this embodiment, since the VTR is paaced in the stop mode before timepoint t₁, the present mode at time point t₁ is the stop mode. Also, thefinal mode and the visual indication thereof are the stop mode.

When the reproducing key is pressed at time point t₁ in FIG. 14, themode transition table in FIG. 12 is looked up by the microcomputer. Thismode transition look-up table in FIG. 12 indicates whether or not, whenthe operation key is depressed, the key input is valid for the finalmode at that time point or if the key input is valid for the final mode,to which mode the mode is to be transferred. Since the final mode is thestop mode at time point t₁ and the key input is the playback mode, itwill be clear from the mode transition look-up table of FIG. 12 that theoperation mode of the VTR should be "PB" (playback mode).

Accordingly, the final mode and the visual indication thereof are madethe playback mode from time point t₁. Further, the VTR (mechanism)starts changing its operation mode from the stop mode into the playbackmode and the present mode is made the playback mode.

When the stop key is pressed at time point t₂ while the VTR is in themode transition period as shown in FIG. 14, the mode transition look-uptable of FIG. 12 is looked up. Since this mode transition look-up tableof FIG. 12 indicates that the mode should be shifted to the stop mode,the final mode and the visual indication thereof are made the stop mode.However, during this period, the VTR itself continues changing itsoperation mode to the playback mode (present mode) which was designatedby the key input at time point t₁.

Further, when the recording key is pressed at time point t₃ during thismode transition period of the VTR, the same mode transition table (FIG.12) is looked up. This mode transition look-up table of FIG. 12indicates that the mode should be shifted to the recording mode. Thus,the final mode and the visual indication thereof are made the recordingmode. However, during this period, the VTR itself continues changing itsoperation mode into the playback mode which was designated by the keyinput at time point t₁.

When at time point t₄ the operation mode of the VTR has finally changedinto the playback mode, the mode transition vector table forming FIG. 13is looked up. This mode transition vector look-up table of FIG. 13indicates whether or not at that time the VTR should further change itsoperation mode and the mode into which the VTR should change itsoperation mode. At that time (at time point t₄ in FIG. 14), since thepresent mode is the playback mode and the final mode is the recordingmode, the mode transition vector look-up table of FIG. 13 indicates thatthe mode of the VTR should be "PB PAUSE" (playback pause mode).Accordingly, the VTR starts changing its operation mode to the playbackpause mode from time point t₄ and the present mode is changed into theplayback pause mode, too.

When the mode transition to the playback pause mode is ended at timepoint t₅, the same mode transition vector table of FIG. 13 is looked up.At time point t₅ in FIG. 14, since the present mode is "PB pause"(playback pause mode) and the final mode is "REC" (recording mode), itwill be clear from the mode transition vector look-up table of FIG. 13that the mode should be "REC PAUSE" (recording pause mode) next.Accordingly, the VTR starts changing its operation mode into therecording pause mode at time point t₅ and the present mode is made therecording pause mode, too.

When the mode transition of the VTR to the recording pause mode is endedat time point t₆ in FIG. 14, the mode transition vector table of FIG. 13is looked up again. At time point t₆ in FIG. 14, since the present modeis the recording pause mode and the final mode is the recording mode,the mode transition vector look-up table of FIG. 13 indicates that thenext mode should be the recording mode. Accordingly, the VTR startschanging its operation mode into the recording mode at time point t₆,and the present mode is made the recording mode, too.

When the mode transition to the recording mode is ended at time pointt₇, the mode transition vector table of FIG. 13 is looked up. At timepoint t₇ in FIG. 14, since the present mode and the final mode are boththe recording mode and equal to each other, the operation mode of theVTR is not change any more. Accordingly, the VTR remains placed in therecording mode after time point t₇.

While the operation mode of the VTR is changed as described above, thismode changing operation of the VTR will be similarly explained by ageneral algorithm which is represented in a flow chart forming FIG. 15.

In other words, this algorithm forms the flow chart (FIG. 15) of aprogram that the microcomputer forming the mode controller 2 (FIG. 3)executes.

Firstly, the presence or absence of a command inputted by pressing anoperation key is checked as represented at decisional step 121. If thepresence of the command is confirmed at step 121, the processing of themicrocomputer (mode controller 2) goes from step 121 to the nextdecisional step 122. It is checked as represented at decisional step 122by the mode transition look-up table of FIG. 12 whether or not the keyinput (command) whose existence was checked at step 121 is valid for thefinal mode.

If it is judged as represented at decisional step 122 that the key inputis valid for the final mode, the processing of the microcomputer goesfrom step 122 to step 123, in which the final mode and the mode visualindication thereof are renewed in accordance with the mode transitionlook-up table of FIG. 12, as represented at time point t₁ in FIG. 14.Then, the processing of the microcomputer goes from step 123 to the nextdecisional step 131.

Also, if the absence of the key input is confirmed as represented atdecisional step 121 or it is judged as represented at decisional step122 that the key input is invalid for the final mode, the processing ofthe microcomputer goes directly from steps 121 and 122 to the nextdecisional step 131.

It is checked, as represented at decisional step 131, whether the modeof the VTR is still shifting or it has already finished. If the mode ofthe VTR is shifting, the processing of the microcomputer goes back fromstep 131 to step 121.

Accordingly, the steps 121 to 123 and the step 131 are repeatedlyexecuted during the period from the time point t₁ to the time point t₄.

If on the other hand it is judged, as represented at decisional step131, that the mode transition of the VTR is already ended, theprocessing of the microcomputer goes from step 131 to the nextdecisional step 132. There, it is checked whether or not the presentmode is equal to the final mode. If they are not equal to each other,the processing of the microcomputer goes from step 132 to step 133. Asrepresented at step 133, the operation mode to which the mode of the VTRshould be newly shifted is determined with reference to the modetransition vector look-up table of FIG. 13, whereby the present mode isrenewed to the new operation mode determined.

Then, the processing of the microcomputer goes from step 133 to step134. The VTR starts changing its operation mode to the present mode,which was renewed as represented at step 133, as represented at step134, and the processing of the microcomputer goes back from step 134 tostep 121.

Consequently, the steps 131 to 134 are executed at time points t₄, t₅and t₆ in the mode transition diagram forming FIG. 14, respectively.

If it is judged, as represented at decisional step 132, that the presentmode and the final mode are equal to each other, the processing of themicrocomputer goes back from step 132 to step 121.

Accordingly, this processing of the microcomputer is executed at timepoint t₇.

According to the processing routine in FIG. 15 as described above, theoperation mode of the VTR is changed as, for example, shown in the modetransition diagram of FIG. 14.

It will be appreciated that the presence or absence of the commandinputted by the operation key can be checked by using a conditionjudging command instead of using the above mentioned mode transitionlook-up table, as represented at decisional step 122 in FIG. 15.

The present invention is not limited to a VTR as mentioned above but canbe applied to various kinds of multi-operation mode electronic apparatussuch as a tape deck, a video disc player, a CD (compact disc) player andthe like which take a lot of time to change their operation modes.

According to the present invention, since the transition mode to whichthe mode of the multi-operation mode electronic apparatus should betransferred is stacked in the mode stack and is optimized, the operationmode of the multi-operation mode electronic apparatus can be changed tothe desired operation mode in the shortest period of time at the timepoint at which the operation key is pressed.

If the key input is valid, the reception of the key input and the visualindication of the operation mode can be immediately executed and thetransition of the operation mode of the multi-operation mode electronicapparatus can be carried out in the shortest period of time, so that theuser never feels that the multi-operation mode electronic apparatus istaking a great deal of time to change its operation mode and thus, theapparent time required by such a mode transition can be removed.Further, the operation mode can be changed to the same final operationmode by pressing the operation key at any timing.

Furthermore, according to the present invention, as set forth above,even if any number of operation keys are pressed, since the operationmode to which the mode of the multi-operation mode electronic apparatusshould be shifted can be made optimum in accordance with the modetransition vector look-up table, the operation mode can be changed tothe desired mode in the minimum number of mode transitions at the timepoint at which the operation key is pressed.

In addition, since the optimization is not required, the processingprogram to be executed by the mode controller 2 can be simplified andthe execution of the program does not take a lot of time. Also, the modestack area becomes unnecessary.

The above description is given for the preferred embodiments of theinvention but it will be apparent that many modifications and variationscould be effected by one skilled in the art without departing from thespirit or scope of the novel concepts of the invention, so that thescope of the invention should be determined by the appended claims only.

We claim as our invention:
 1. A method for changing the operation modeof an multi-operation mode electronic apparatus during a period in whichthe operation mode is transferring from a present operation mode to afinal operation mode, comprising the steps of:(a) receiving an inputcommand signal; (b) judging whether said input command signal is validor not in view of the operation mode corresponding to previouslyreceived, valid command signals; (c) redetermining the final operationmode in accordance with said valid input command signal; (d) determininga sequence of mode changes from the present operation mode to the finaloperation mode; and (e) executing said sequence of mode changes untilsaid present operation mode is equal to said final operation mode.
 2. Amethod according to claim 1 wherein said step of receiving comprisesstoring in an electronic memory device a plurality of said input commandsignals and said step of determining comprises the step of optimizingsaid input command signals according to predetermined criteria.
 3. Amethod according to claim 1 wherein said steps of determining andexecuting are performed by electronically accessing a transition vectorlook-up table stored in an electronic memory device.
 4. A method forchanging the operation mode of an multi-operation mode electronicapparatus as recited in claim 1 wherein the step of judging the validityof the input command signal comprises determining that the followinginput commands are invalid with respect to the following correspondingfinal modes:

    ______________________________________                                        FINAL MODE  INPUT COMMAND                                                     ______________________________________                                        STOP        STOP                                                              FAST FWD.   FAST FWD., PAUSE, REC.                                            REW.        REW., PAUSE, REC.                                                 PLAYBACK    FAST FWD., REW., PB, REC.                                         PB PAUSE    FAST FWD., REW.                                                   RECORD      FAST FWD., REW., PB, REC.                                         REC. PAUSE  FAST FWD., REW., PB, REC.                                         ______________________________________                                    


5. A mode processing circuit for a multi-operation mode electronicapparatus comprising:means for generating input command signals; modestack means having a plurality of stages for storing each said inputcommand signal as an operation mode for said multi-operation modeelectronic apparatus; means for storing said operation modes in saidmode stack means in a sequential order and for optimizing the sameaccording to predetermined criteria; and means for deriving saidoperation modes from said mode stack in the sequential order and thenexecuting the same after the transition of said multi-operation modeelectronic apparatus to each operation mode is ended.
 6. A modeprocessing circuit for a multi-operation mode electronic apparatuscomprising:transition vector look-up table means for indicating aoperation mode to which the operation mode of said multi-operation modeelectronic apparatus should be shifted; means for receiving an inputcommand signal and determining a final mode of said multi-operation modeelectronic apparatus in accordance therewith; means for determining anew operation mode to which the operation mode of said multi-operationmode electronic apparatus is to be shifted next from said final mode anda mode to which the operation mode of said multi-operation modeelectronic apparatus was shifted with reference to said transitionvector look-up table means; and means for changing the operation mode ofsaid multi-operation mode electronic apparatus to said operation modethus determined and then placing said multi-operation mode electronicapparatus in said final mode.
 7. A mode processing circuit for amulti-operation mode electronic apparatus as recited in claim 6, whereinsaid transition vector look-up table means comprises an electronicmemory which stores the following transition mode commands:

    ______________________________________                                        Present mode                                                                           Final mode  Transition Command                                       ______________________________________                                        STOP     PB PAUSE    STOP TO PLAYBACK                                         FAST FOR-                                                                              PB PAUSE    FAST FWD. TO PB                                          WARD                                                                          FAST FOR-                                                                              RECORD      FAST FWD. TO STOP                                        WARD                                                                          FAST FOR-                                                                              REC. PAUSE  FAST FWD. TO STOP                                        WARD                                                                          REWIND   PB PAUSE    REWIND TO PB                                             REWIND   RECORD      REWIND TO STOP                                           REWIND   REC. PAUSE  REWIND TO STOP                                           PLAYBACK RECORD      PB TO PB PAUSE                                           PLAYBACK REC. PAUSE  PB TO PB PAUSE                                           PB PAUSE FAST FWD.   PB PAUSE TO STOP                                         PB PAUSE REWIND      PB PAUSE TO STOP                                         PB PAUSE RECORD      PB PAUSE TO REC. PAUSE                                   PB PAUSE REC. PAUSE  PB PAUSE TO REC. PAUSE                                   ______________________________________                                    


8. A mode processing circuit for a multi-operation mode electronicapparatus as recited in claim 6 or 7, wherein said transition vectorlook-up table means comprises an electronic memory which stores thefollowing transition mode commands:

    ______________________________________                                        Present mode                                                                             Final mode  Transition Command                                     ______________________________________                                        RECORD     REWIND      RECORD TO STOP                                         RECORD     FAST FWD.   RECORD TO STOP                                         RECORD     PLAYBACK    RECORD TO STOP                                         RECORD     PB PAUSE    RECORD TO STOP                                         REC. PAUSE REWIND      REC. PAUSE TO STOP                                     REC. PAUSE FAST FWD.   REC. PAUSE TO STOP                                     REC. PAUSE PLAYBACK    REC. PAUSE TO STOP                                     REC. PAUSE PB PAUSE    REC. PAUSE TO STOP                                     ______________________________________                                    